function Parent3() {
    this.name = 'parent3';
    this.play = [1, 2, 3];
}
function Child3() {
    Parent3.call(this);
    this.type = 'child3';
}
Child3.prototype = new Parent3();
var s3 = new Child3();
var s4 = new Child3();
console.log(s3,s4);
s3.play.push(4);
console.log(s3.play, s4.play);